Phenology, Agrometeorological Indices and Yield of Pusa Basmati-1509 as Influenced by Sowing Dates and Nitrogen Levels under Temperate Conditions

The purpose of the study was to optimize the sowing date and nitrogen level in early maturing rice (Pusa basmati 1509) under temperate climate for realizing higher yield. The experiment was conducted on silty clay loam soil, neutral in reaction, low in available nitrogen, medium in available phosphorus, potassium and organic carbon. Treatments included three sowing dates viz 20th April, 30th April, and 10thMay and five nitrogen levels viz 0, 30, 60, 90 and 120 kg N ha-1 laid out in split plot design with three replications. Among the sowing dates, 20th April took maximum no. days to reach different phenological stages and maturity. The GDD (1431) and HTU (15161 oC d-1 hr-1) requirement to reach maturity was maximum for 20th of April sowing. Significantly higher grain yield, higher HUE (2.90 kg ha-1 oC-1 d-1) and HTUE (0.273 kg ha-1 oC-1 hr-1) was realized form 1st date of sowing i.e., 20th of April. Higher doses of 120 kg N ha-1resulted in slightly more number of days to reach different phenological stages and maturity that was also reflected in higher accumulation of more GDD 1403° and HTU (14987 °C d-1 hr-1) at maturity. Highest HUE (1.42 kg ha-1 oC-1 d-1) and HTUE (0.133 kg ha-1 °C-1 hr-1) was realized at 120 kg N ha-1. Further among the sowing dates, 20th April and 30th April had significantly higher growth parameters viz. plant height, leaf area index, tillers m-2, dry matter accumulation, leaf area index and SPAD reading as compared to 10th May. Most of the growth and yield parameters were found significantly higher at nitrogen level of 120 kg ha-1. However, most of them were at par with followed by nitrogen level of 90 kg ha-1.